Re: FPGATED prototype

From: Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de>
Date: Sun, 17 Jan 2021 12:58:52 +0100
Message-ID: <eba61136-fe0c-9d1f-bb7a-7ffcf5da658a_at_laosinh.s.bawue.de>
On 1/17/21 12:34 PM, Istvan Hegedus wrote:
> Hi Jim,
> Ok I send you a PM. Note however that I need the 48 pin one. 40 pin one is
> good for 8501 replacement.

You should also be able to use 2 x 24pin type. I have done that with 
sockets when replacing the TED socket on 264 systems.

  Gerrit






> Thanks
> Istvan
> 
> On Sat, Jan 16, 2021 at 7:24 PM Jim Brain <brain_at_jbrain.com> wrote:
> 
>> On 1/16/2021 4:15 AM, Istvan Hegedus wrote:
>>
>>
>>>
>>> I can't argue the smaller footprint FPGA and 4 layer PCB, but I'd keep
>>> the surface mount header.  I think they look much more neat in circuit
>>> and if you trim the outside of your PCB to just beyond the SMT pins, I
>>> don't think the design will be too wide.  Having the pins sticking
>>> through reduces top PCB area a lot and then you have to worry about
>>> cutting the pins off and making sure they do not touch metal shields and
>>> such if folks re-assemble the EMI stuff.
>>>
>>> Jim
>>>
>>> You are right, if I use through hole header then I don't have much space
>> left on the two sides for routing and components.
>> I will consider it. There are only 2 drawbacks, price of the smd IC header
>> and the lead time (I have ordered it at Mouser in november and they promise
>> it now at the end of feb).
>>
>> Regards
>> Istvan
>>
>> I plan to buy 1000 of the SMT ones (I have the 28 pins in SMT and through
>> hole and the 24 in through hole and plan to buy in SMT as well) and am
>> happy to  set aside 100 or so for you if desired.  You can directly email
>> me for pricing, but I can't believe 40 pins of smt header would be no more
>> than 1.25 USD, and probably $1.00 (from my supplier, SMT and though hole
>> differ in price by only a few pennies), which looks far cheaper than Mouser
>> options (not sure why Digikey and mouser are so expensive on IC headers).
>> Lead time is about 2-3 weeks. I can mail you a few 28 pin ones to check on
>> quality if desired.
>>
>> You can see what the through hole ones look like here:
>>
>> http://store.go4retro.com/ic-header/
>>
>> And the SMT ones look the same on the bottom, but the upper post is bent
>> out 90 degrees like in your footprint.
>>
>> Don't worry if you're not interested.  I plan to buy the 40 pin SMT ones
>> either way and use for other projects.  Just let me know your thoughts.
>>
>> If others are looking for non trivial connectors, let me know. I regularly
>> source in bulk and if I can put it in the store or think up a use in a
>> product, happy to buy 1000 of them (1000 is typically the minimum order
>> quantity for manufacturers).
>>
>>
>> Jim
>>
>>
>>
>> --
>> Jim Brainbrain_at_jbrain.com www.jbrain.com
>>
>>
> 
Received on 2021-01-17 13:02:06

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